Private Sub Command1_Click()
    'PROGRAM D4R15
    'Driver for routine BESSJ0
    Open "D:\VB常用數值算法集\DATA\FNCVAL.DAT" For Input As #1
    Do
      Line Input #1, Text$
    Loop While Text$ <> "Bessel Function J0"
    Line Input #1, NVAL$
    NVAL = Val(NVAL$)
    Print Text$
    Print
    Print "     X      Actual      BESSJ0(X)"
    For I = 1 To NVAL
        Line Input #1, DUM$
        X = Val(Mid(DUM$, 1, 6))
        Value = Val(Mid(DUM$, 7))
        Print Tab(4); Format$(X, "#0.0#");
        Print Tab(12); Format$(Value, "##.0000000");
        Print Tab(25); Format$(BESSJ0(X), "##.0000000")
    Next I
    Close #1
End Sub